Transformer for electric arc cutting, repairing, and welding apparatus



July 31. 1928. 1,679,263

F. C. OWEN TRANSPORIER FOR ELBGTRIC ARC CUTTING, REPAIRING, AND WELDIHG APPARATUS Filed April 19. 1927 2 Sheets-Sheet 1 July 31, 1928. 1,679,263

F. c. OWEN TRANSFQMR FOR ELECTR IC ARC CUTTING; REPAIRING, AND WELDING APPARATUS Filpd April 19, 1927 2 Sheets-Sheet 2 35 33 T3: g. E.

gmento'o Patented July 31, 1928.

UNITED STATES PATENT OFFICE.

FREDERICK G. OWEN, OI FAYETTEVILLE, NORTH CAROLINA.

TBANSI'OBIEB FOB ELECTRIC ARC CUTTING, REPAIRING, AND WELDING APPARATUS.

Application fled April 19, 1827. Serial No. 185,010.

This invention relates to improvements in the transformer forming the subject-matter of my U. S; Letters Patent, No. 1,619,753, granted March 1, 1927. This transformer 1s especially adapted for use in connection with electric are cutting, repairing and welding apparatus, and embodies a closed circuit core, a primary wi ding distributed about a portion of the core, a main secondary coil on such portion of the core and adapted to be connected to the electrode of the apparatus, and an auxiliary secondary coil on the other portion of the core and adapted to function as an impedance coil and to be connected to the work. This transformer functions to automatically induce in the secondary circuit a light current or voltage at light load and a heavy current or voltage at hea load with the result that a stable arc of high power factor may be readily maintained.

The present invention has for one of its objects to improve this transformer to the end that a nicer or finer regulation of the current or voltage delivered to the arc may be attained, and to attain this end comprehends the provision of means by which the impedance of the auxiliary secondary c011 may be varied manually.

With the foregoing and other objects in view, the nature of which will become apparent as vention consists of the constructlon, combination and arrangement of parts hereinafter fully described and claimed, and illustrated in the accompanying drawings, wherein:

Figure 1 is an elevational view of an electric are cutting, repairing and welding apparatus embodying a transformer constructed in accordance with the present invention,

and

Figure 2 is a similar view of the apparatus equipped with a slightly. modified form of the transformer.

The core of the transformer comprises a fixed rectangular section 1 and an ad ustable straight section 2 both of which are of laminated construction. The top leg of the core section 1 is designated 3, the bottom leg 4 and the side legs 5 and 6. The leg 6 is provided with relatively, spaced polar projections 7 which are located at the outer vertical side thereof. The core section 2 which is slidably supported opposite the polar .projections 7,

the description proceeds, the in-- is provided with polar projections 8. The core section 2 is slidably supported by a suitable guide 9, and s adapted to be operated to effect the adustment of its polar projections 8 with respect to the polar pro ections 7 through the medium of a hand screw 10 which is suitably connected thereto and journaled in a suitable support 11.

The primary winding of the transformer comprlses connected coils 12, 13 and 14 which are arranged on the legs 3, 4 and 5, respectively. The coils 12' and 13 are adapted to be connected to a source of alternating current by leads 15 and 16.

The secondary winding of the transformer comprlses a main or voltage regulating coil 17 arranged on the leg 5, an auxiliary or current regulating coil 18 which is connected to the main or voltage regulating coil 17 and which consists of sections 19 and 20, the section 19 being arranged upon the leg 6 between the polar projections 7 and the section 20 on the core section 2 between the polar projections 8. The core section 19 is provided with tap leads 21, to anyone of which may be connected a lead 22 which is connected to the coil section 20. The coil section 20 is provided with tap leads 23, and a. lead 24 which may be connected to anyone of the tap leads 23 is connected to the work 25 to be cut, repaired or welded. The coil 17 is provided with tap leads 17 to any one of which may be connected a lead 26 extending to the cutting, repairing or weldingvelllectrode 27.

en the apparatus is in use, current flowing through the primary winding, which consists of the coils 12, 13 and 14 and is distributed about the major portion of the core section 1, tends to cause a magnetic flux to circulate through the four legs of said core section and through the core section 2. Practically all of the primary-flux developed by this winding will thread the main or voltage regulating coil 17 of the secondary winding, because of the close association of said coil to the primary winding, and the flux in the legs 3, 4 and 5 about which this coil and the primary winding are distributed, remains substantially constant at all loads. As the result, the voltage generated in the main or voltage regulating coil 17 of the secondary winding likewise remains practically the same at. all times, and does not vary with the load.

The auxiliary or current regulating coil 7 18 of the secondary winding, however, being remote from the primaiy winding, tends to set up a llux independent of and opposed to that generated by the primary windin Owing to the location of the coils of both windings, this secondary flux is confined substimtially to the leg 6 of the core section 1 and to the core section 2 on which the auxiliary or current regulating coil 18 of the secondary winding is mounted, while the primary tux alone threads the legs 3, 4 and 5 of the core section 1, and, as a result, the reau'tion'between the primary and secondary fluxes takes place in the leg 6 and core section 2. The reac tion between these fluxes causes a substantial amount of flux to be forced out of the core sections 1 and 2 into the air, or in other words at the ends of the leg 6 and the ends of the core section 2, or in other words, a very noticeable flux leakage takes place at these points. The larger the current drawn from the secondary winding, the greater the flux leakage becomes.

As a result of" the reaction between the primary and secondary fluxes which takes place in the leg 6 and core section 2, the heavy secondary flux causes the auxiliar or current regulating coil 18 of the secon ary winding to develop high inductance, and acts as an impedance coil, so that the phase of the voltage in this part of the secondary winding is shifted. It will thus be understood that, when current flows through the primary winding, a constant main voltage and a variable secondary voltage are induced in the secondary winding. The reaction between these voltages is such that there is induced, in the secondary circuit,

including the work 25 and. electrode 27, a

light current at light load and aheavy current at heavy load, with the result that a stable arc of high power factor may be readily maintained during overhead, vertical and horizontal cutting, repairing or welding of steel, wrought iron, cast iron, malleable iron, aluminum, brass, bronze, copper and other allo metals. Furthermore, the arc is free rom sputtering and spitting, and it has been found that a skilled operator can maintain an are within one and one-half per cent plus or minus of the rated capacity of the tap with which the electrode is connected.

The value of the current or voltage delivered to the arc may be varied manually by altering the impedance of the auxiliary or current regulating secondary coil 18, and this may be accomplished by adjusting the core section or unit 2 with respect to the core section or unit 1, so as to vary the position of the polar projections 8 with respect to the polar projections 7.

The transformer shown in Figure 2 comprises acore unit 1 and acore unit 2 both of which is mounted on the logo, and an auxiliary or current regulating coil which consists of sections 19, 20 and 20". The section 19' is mounted on the leg 6 of the core 'unit 1, and the sections 20 and 20" are mounted on the polar projections 29 and 31, respectively, of the core unit 2. The section 19 is provided with taps 32 and the section 20 with taps 33 to permit the entire sections or portions thereof to be connected in circuit by a lead 34. The section 20 is provided with taps 35, and a lead 36 may be connected to any one of these taps and to any one of the taps 33 so as to connect the entire sections 20 and 20 or portions thereof in circuit. A lead 24; which may be connected to any one of the taps 35 is connected to the work 25,- and a lead26f which may be connected to any one of the taps 17 of the coil 17 is connected to the electrode 27.

This transformer functionssimilar to the transformer shown in Figure 1, and the impedance of its auxiliary or current regulating secondary coil 18 may be varied by varying the position of the polar rojections 31 with respect to the polar pro ections 28, and this may be done by turning the rotor 30 through the required angle.

What is claimed is I 1. A transformer comprising a core embodying relatively fixed and adjustable sections, a primary winding, a secondary winding embodying main and auxiliary coils the auxiliary coil embodying sections of which one is mounted on the fixed and the other On the adjustable core section, and means for moving the adjustable core section with respect to the fixed core section.

2. A transformer comprising a core embodyingrelatively fixed and adjustable sections provided with polar projections, a primary winding, a secondary winding embodying main and auxiliary coils, the auxiliary coil embodying sections of which one is mounted on the fixed and the other on the adjustable core section, and means for moving the adjustable core section with respect to the fixed core section.

3. A transformer comprising a core embodying relatively fixed and adjustable sec-- tions provided with polar projections, a primary winding, a secondary winding embodying main and auxiliary coils, the auxiliary coil embodying sections of which one is mounted on the fixed core section between the polar projections thereof and of which the other 1s mounted on the adjustable core section between the polar projections thereof, and means for moving the adjustable core section with respect to the fixed core section.

4. A transformer comprising a relatively fixed core section, a primary coil on a part of the core section and adapted to cause substantially all the primary flux to traverse the other part thereof, polar projections on said other part of the core section, a secondary coil section on said other part of the core section, a second secondary coil connected to said core section and arranged on that part of the core section on which the primary coil is mounted, a relatively adjustable core section provided with polar projections, and a second secondary coil section mounted on the adjustable core section and connected to said first core section.

5. A transformer comprising a core section providing a closed magnetic path, a primary coil on a part of the core section and adapted to cause substantially all the primary flux to traverse the other part of the core section, a second core section positioned adjacent said other part of said first core section, a secondary coil distributed about said second core section and said other part of said first core section, means b which one ofthe core sections may be adjusted with respect to the other, and a second secondary coil connected to said first secondary coil and arranged on that part of the core on which the primary coil is mounted.

6. A transformer comprising a primary winding, and a secondary winding embodying a main coil and an auxiliary coil of which the latter consists of relatively adjustable sections.

In testimony whereof I aflix my signature.

FREDERICK G. OWEN. 

